Depending on which media outlet you believe, Vista is either doing poorly or doing so well that it's hurting OS X sales:
"Vista promised better performance, reliability, security, and a revolutionary user interface - but it appears consumers looking to upgrade are not ready to buy into the promise," said Harris VP Milton Ellis.
Windows Vista more than doubled its market share in March from the prior month, while the share of computers running Mac OS X fell for the first time in nine months, according to statistics released Thursday by market research firm Net Applications. [original source: Computerworld]
I think that CW is primarily a PC-related outlet, so maybe they have an axe to grind against Apple. No matter what, MS is still following Apple's lead in every way. So for a company that's falling further behind MS, Apple sure is dictating how the market goes:
Following digital music pioneer Apple's lead yet again, Microsoft said this week it will soon sell digital music online without DRM (digital rights management) protection.